Hi ahans123,
Are you using the devkit or custom board for Orin Nano?
The SPI driver in JP6 is from upstream so that some custom features have been removed.
For the CS related issue in SPI driver of JP6, please apply the patch in Jetson orin nano SPI Speed not changing - #9 by KevinFFF for the fix.
If you have further questions about using SPI in JP6, please let us know and share the detailed reproduce steps.